Magnetic resonance imaging (MRI) may be useful in evaluating hypovascular nodules of the liver, according to research published in the European Journal of Gastroenterology & Hepatology.
Differentiating malignant from benign types of hypovascular nodules, defined in the report as “nodules with large areas of hypointensity on the arterial and portal venous phases of dynamic enhancement, which was the same as or less than that of adjacent liver,” has become more important as imaging and detection of these lesions has improved over time, said senior author Guangwu Lin, MD, PhD, of the Department of Radiology of Huadong Hospital, Fudan University in Shanghai, China, and colleagues. “The liver is both a principal site of primary malignancies and a major target of metastatic disease from almost any primary malignant neoplasm,” they wrote. “In addition, the incidence of benign hepatic lesions is high in the adult population.”
Dr Lin and fellow investigators retrospectively studied 135 patients (57 women and 78 men; age, 21-91 years; mean age, 56 ± 13 years) with solitary hypovascular hepatic lesions that were 3 cm or less (mean diameter, 1.8 ± 0.7cm); 55 had malignant lesions (mass-forming intrahepatic cholangiocarcinomas, 29 patients; hepatic metastases, 26 patients), and 80 had benign lesions (inflammatory pseudotumors and solitary necrotic nodules, 48 patients; hepatic hemangiomas, 32 patients). The investigators found significant differences between malignant and benign hypovascular hepatic nodules. Statistically common findings for the benign lesions were subcapsular, sharp margin, homogeneous, marked high signal on T2-weighted image, mild hyperintensity on T2-weighted image, increasing intensity of peripheral globular enhancement, and persistent central septum-like linear enhancement on delayed phase, the authors wrote. For malignant nodules, the authors said the most common findings were ill-defined margins, heterogeneity, decreasing intensity of peripheral rim-like enhancement, and centrally increasing intensity of patchy enhancement.
In addition, Dr Lin and colleagues noted some of their findings could be helpful in the differentiation of intrahepatic cholangiocarcinoma, which is a common primary hepatic cancer that can be mistaken for benign lesions. “Currently, intrahepatic cholangiocarcinoma accounts for ∼15% to 20% of all primary liver cancers and is the second most common primary hepatic tumor worldwide,” they wrote. “When visualized by MRI, because of the similarity of intrahepatic cholangiocarcinoma to some benign lesions, it may lead to delayed cholangiocarcinoma diagnosis. The most common enhancement feature of intrahepatic cholangiocarcinoma was a peripheral rim enhancement pattern during the arterial phase, followed by progressive and concentric filling with contrast material and patchy enhancement on delayed phases.”
- Qian H, Li S, Ji M, Lin G. MRI characteristics for the differential diagnosis of benign and malignant small solitary hypovascular hepatic nodules. Eur J Gastroenterol Hepatol. 2016;28:749-756.